The present invention relates to dispensers for delivering doses of compositions. In particular, the invention relates to dispensers for the delivery of metered doses of compositions from a squeezable container.
The present invention is especially useful for delivering accurate doses of prescription or non-prescription medications that are supplied in tubes or other squeezable containers. For example, the invention includes but is not limited to, the delivery of accurate and consistent doses of estrogen creams. Estrogen creams are commonly used by women to treat vulvar atrophy, atrophic vaginitis, atrophic urethritis, and other postmenopausal conditions. When used on the skin or vagina, most estrogens are absorbed into the bloodstream and cause some of the same therapeutic effects as when they are taken orally. Side effects of estrogen creams include breast pain, itching of the vagina, enlarged breasts, headache, nausea, and vaginal discharge. Estrogen creams are available over-the-counter and are supplied in varying concentrations of the estrogen hormone. There is a need for the provision of accurate doses of estrogen cream to achieve the desired therapeutic effect and to prevent side effects. Additionally, there is a need for a delivery system that allows for a dosage change should it be necessary to achieve the desired effect, to prevent or ameliorate side effects, or to accommodate a substituted product with a different estrogen concentration.
U.S. Pat. No. 4,416,397 (Brown) described a sealed delivery system, with an elongated inlet passage and an elongated outlet passage, for dispensing a metered amount of viscous or semi-fluid material from a tube. Brown described a sealed, tamperproof system, which provided for maintenance of product sterility. Sterility is not a requirement for topical skin or vaginal delivery systems. The sealed system in general and as taught by Brown does not allow for disassembly and, therefore, precludes part substitution for dose alteration, replacement for wear and tear, and replacement for soilage. Disassembly also provides for ease of cleaning.
Likewise, the elongated inlet and outlet passages of Brown result in unusable amounts of often expensive medications because the medication is lost to the dead space of the system. Systems with elongated inlet and outlet passages require greater pressure to be applied to the source to cause delivery of product from the outlet passage than is required in a more compact system. An elongated outlet passage results in variable and inaccurate dosing of lower viscosity product because of varying delivery amounts of product from the elongated outlet passage due to variable leakage at time of delivery.
The prior art does not describe a delivery system that dispenses consistent and accurate dosages, and that may be disassembled to allow for alteration of the metered dose amount, cleaning between uses or for storage after use, and part replacement.
The present invention is directed to a system for the delivery of adjustable metered doses of a composition from a squeezable container. An advantage of the present invention is that it overcomes the disadvantages of the prior art. Another advantage is that the present invention conserves the composition. Another advantage of the present invention is ease of delivery. Additionally, an advantage of the present invention is that the present invention is available for repetitive, remote uses.
These and other advantages of the present invention are achieved by a metered dose dispenser including a body that includes an inlet channel with a first opening, an outlet channel with a second opening, and a dosing wheel seat. The dosing wheel seat is a cavity defined by the body. The dosing wheel seat communicates with the inlet channel, via the first opening, and with the outlet channel, via the second opening. The metered dose dispenser also includes a removable, rotatable dosing wheel that is situated within the dosing wheel seat when the metered dose dispenser is in use. The dosing wheel includes a dosing channel, which may be aligned with the inlet channel and the outlet channel. A plunger is movably situated in the dosing channel, the plunger does not fit through either the first or second opening.
These and other advantages of the present invention are additionally achieved by a metered dose dispenser including a body that includes an inlet channel with a first opening, an outlet channel with a second opening, and a dosing wheel seat. The dosing wheel seat is a cavity defined by the body located between the inlet channel and the outlet channel. The dosing wheel seat communicates with the inlet channel via the first opening and with the outlet channel via the second opening. The metered dose dispenser also includes a rotating dosing wheel that is situated within the dosing wheel seat when the metered dose dispenser is in use. The dosing wheel includes a dosing channel, which has a first end and a second end that are alternatively aligned with the first opening and the second opening. The dosing channel is longer than the inlet channel and the outlet channel. A plunger is movably situated within the dosing channel. The plunger does not fit through either the first opening or the second opening.
These and other advantages of the present invention are also achieved by a kit including a set of interchangeable dosing wheels with varying diameter dosing channels, wherein the dosing wheel may be replaced with any one of the set of interchangeable dosing wheels.
These and other advantages of the present invention are also achieved by a kit including a set of interchangeable plungers of varying lengths, wherein the plunger may be replaced with any one of the set of interchangeable plungers.